The Pajaro River watershed covers approximately 1300 square miles and spans 4 counties: San Benito, Santa Clara, Santa Cruz, and Monterey. The watershed is bound by the Santa Cruz Mountains to the North, and the Gabilan Range to the South. Its main tributaries are Corralitos, Uvas, Llagas, San Benito, Pacheco, and Santa Ana creeks. These tributaries and many others converge and provide water to the Pajaro River, which drains into Monterey Bay.
Because the Pajaro River watershed spans four counties and four water districts, politics and different interests have complicated jurisdictional boundaries and enforcement of laws pertaining to water use, environmental protection, etc. One advantage of this large geographic scale and political complexity is the knowledge and energy represented by the numerous and active Pajaro River Watershed organizations.
When studying the characteristics of water quality, water supply, and flood hazard in a region, it makes most sense to look the entire area covered by the watershed. A watershed, also known as a drainage basin, is the total area that contributes water to a single point. The point is usually the lowest point in the watershed, taking the form of a river or a reservoir. Watersheds are bound by high regions such as mountain ridges or hills.
There are 2,267 Enviromental Protection Agency (EPA) designated watersheds in the United States. Every watershed within the US has a unique 8 digit Hydrologic Unit Code (HUC) used to catalog the data associated with it. The code for the Pajaro River watershed is 18060002. To find more information about the Pajaro River watershed, go to: